Respiratory apparatus



July 20, 1943.

M. E. NOHL RESPIRATORY APPARATUS 'Fil ed Feb. 23, 1939 2 Sheets-Shet 1 vINVENTQR Max Eueaws NOf/ .L. MUMW M MMQMWM IM July 20, 1943. M. E. NOHLRESPIRATORY AFPARATUS Filed Feb. 25, 1939 2 Sheets-Sheet 2 J INVENTORMax 5055M; NOHA BY V M VMVM ATTORNEY5 Patented July 20, 1943 UNITEDSTATES PATENT OFFICE RESPIRATORY APPARATUS Max Eugene Nohl, Milwaukee,Wis.

Application February 23, 1939, Serial No. 257,983

13 Claims.

This invention relates to improvements in respiratory apparatus.

The device may be used for diving in water in the form of a diving suit,helmet or mouthpiece, or diving bell. In the alternative, the device maybe used to promote proper respiratory pressure conditions in tunnels orother enclosures.

It is the object of the invention to provide novel and improved meansfor supplying in prope proportions and at proper pressures any naturalor artificial mixture of oxygen with other gases for respirationpurposes, such mixture be ing hereinafter referred to as air, whether itconsists of oxygen and nitrogen or, as is preferred for diving purposes,of a mixture of oxygen with helium, or some other relativelyphysiologically inert gas.

More specifically, it is one of the objects of the invention to provide,in preferred embodiments, two sources of gas available to. therespiratory organs of the user, one source pref erably constituting pureoxygen delivered at a substantially constant rate to replace the oxygenconsumed to meet metabolic requirements, and the other source comprisingair supplied under the direct control of the operator to main tain theappropriate pressure in the dress or chamber without altering the ratioof oxygen.

It is another specific object or" the invention to provide a circulatoryrespiratory system with means for handling the variation of displacementoccasioned by the breathing of the operator, and means for automaticallyremoving carbon dioxide impurities and replacing the consumed oxygen ata substantially constant rate irrespective of pressure, the pressurebeing separately controllable by the operator.

Anothe specific object of the invention is to provide a device of thischaracter with suitable automatically and manually controllable meansfor regulating the constituent proportions, direction of flow, andpressure of gases in a closed system which are used for respiration byan op- Fig. 2 is a diagrammatic view of a portion of the apparatus shownin Fig. 1 as it appears on the line 2-2 of Fig. 1.

Fig. 3 is a View similar to Fig. 2 showing fragmentarily a modifiedembodiment of the invention.

Fig. 4 is a fragmentary view in side elevation, of a further modifiedembodiment of the invention used particularly for shallow diving'or formine work.

5 is a view on an enlarged scale showing diagrammatically in section thedevice illustrated in Fig. 4.

Fig. 6 is a'view in section through a diving bell in which the inventionis incorporated.

' Fig. '7 is a detail view of a modified gauge for indicating theproportionate constituents of the air.

Like parts are identified by the same reference characters throughoutthe several views.

The suit shown in Fig. 1 is of special construction. It is made in threeunits to comprise a helmet ID, a jacket I I, and a pants unit 12. Theunits I0 and H are connected together in the manner indicated in sectionin Fig. 1. The jacket unit ll is made of flexible material such asrubber, ending in a tubular neck portion i5 which is beaded over at Itto engage over the shouldered terminal tube ll of the helmet and isclamped thereon by the clamp ring it. A similar clamp ring i9 is used atthe waist of a diving suit to hold the pants unit-and jacket unittogether. The jacket unit is provided with tight cuiis or with integralmitten or gloveextensions 20 and the pants unit has integral shoe orboot extensions at 2: so that the whole suit is hermetically sealedabout the operator. The space within the flexible diving dresscommunicates freely with the space within the helmet.

The respiratory apparatus comprises a mask at 25 which fits closelyabout the mouth, or mouth and nose, of the operator so that the airwhich he breathes is not drawn directly from the interior of the suitbut from the valve chamber 26 into which he also respires. The plug 21removably screwed into the front of valve chamber 26 furnishes a speedyway of giving the operator access to exterior air when desired.

The valve chamber 26 communicates at one side with the intake chamber 28which in turn communicates through opening 29 with the interior of thehelmet and consequently with the entire interior of the suit. A checkvalve at 3!! prevents any return of gases to the suit through the intakechamber 28.

At the other side the valve chamber 26 communicates through check valve3| with an outlet chamber 32 from which a pipe 33, preferablyconstructed integrally with the helmet, at the exterior thereof, leadsaround the helmet, to the rear, where connections are made to a flexiblepipe 34. A similar fiexible pipe leads the purified return air back intothe diving suit through the rear of the helmet.

The pipes 34 and 35 afford communication with the air proportioning,purifying. and pressure regulating mechanism carried by the case 35which is suspended, as by chains 3'], on the operators back. Themechanism which may desirably be housed within the case 35 is showndiagrammatically in Fig. 2 without any efiort to show the parts in anynecessary relative position, the arrangement being a matter of design.

The exhaled air delivered through pipe' 34 to the case 36 passes to thebottom of a canister 38 which may be filled with any usual means (such.as soda and lime) of absorbing carbon dioxide.

Lime is one of the ingredients usually used for this purpose. Theexhaled breath of the operator passes upwardly through the lime or otherchemical purifying agent incorporated at 33in the canister and issuesfrom the top of the canister into pipe 35 for return to the diving suit.

It will be understood that when the air was taken into the operatorslungs its oxygen was consumed and carbon dioxide was substituted. 1Consequently the removal of the carbon dioxide from the air in thecanister 38 leaves the air with insufiicient oxygen to supply therequirements of the operator.

Consequently a flask of oxygen under high pressure is supplied at 40within case 36. A

cut-off valve 4| controls the flow of the oxygen .to the reducing valve42 in which its pressure is cut down to any desired low level which themetering apparatus can conveniently handle. Another manually controlledvalve may be incorporated at 43 in the pipe 44 which leads to themetering orifice 45.

,At any given setting of reducing valve 42 the orifice at 45 will passoxygen at a substantially constant rate of fiow to pipe 45 which leadsto pipe 35, whereby the oxygen is mingled with the oxygen-depleted airwhich is being restored from the canister to the diving suit. The entireinterior of the diving dress acts as a mixing chamr ber within which theoxygen is freely mixed with the depleted air before being consumed bythe operator through the mask 25 as previously described. The divingdress also acts as a bellows, expanding and contracting slightly tocompensate for the expansion and contraction of the operators lungs ashe breathes. There is really very little bellows movement of the divingdress required because the operator, as he breathes, moves his chest anddiaphragm in such a Way as to increase the space within the diving dressin proportion to the decrease of capacity of hislungs and vice versa.

A pressure gauge at 48. enables the operators assistants .to know,before he commences his dive, how much pressure he is supplying throughthe reducing valve 42, and consequently the rate of oxygen flow-isreadily ascertainable. Such .a gauge might be mounted inside the helmet.for observation by the diver or might be omitted or removed when theproper fiow has been. determined.

For emergencies a by-pass valve is providedat 49 in the by-pass pipe 59whereby the operator can supply himself with additionaloxygen-asdepiece.

sired to compensate for any special exertion on his part withoutchanging the metered flow of oxygen as established by the reducing valve42 and the metering orifice 45.

It is a big advantage of the type of respiratory apparatus hereindisclosed that it is not necessary to use air as a means of supplyingfresh oxygen, and it is not necessary to use undiluted oxygen as a meansof compensating for the increased pressures encountered in submersion.

Pressures are compensated for by a separate supply of air under pressurein the container 52 which has a cut-off valve 53, a reducing valve 54,and a manually operable exposed cut-oil valve 55 which the operator maymanipulate at will to valve chamber 260 from which the exhaled airpasses through check valve 3| to the outlet chamber'32 and thencethrough pipe 330 to a container which he carries on his back and whichholds the apparatus shown in Fig. 1 and Fig. 2. The purified andre-oxygenated air is returned through pipe 350 directly to the inletchamber 38 where it enters the valve chamber 250 subject to control bythe check valve 30. In this instance a bellows 58 is connected to thereturn pipe 350 as a means of receiving surplus air during theexhalation of the operator and supplying the gases to the operatorduring his inhalation, thus making it possible for the operator to keephis nose closed and to breathe in and out through his mouth in a closedrespiratory system which functions without loss of air.

Still greater simplification is achieved in the device shown in Fig. 4and Fig. 5, in which the valves are not directly associated with themouth- In this device the mouthpiece 51 corresponds exactly with thatshown in Fig. 3, as do the pipes 330 and 359 which receive gases fromand return air to the mouthpiece. Within the case 360 pipe 333terminates in a rubber check valve 59 of well known type which isdisposed in one end of the canister 380. Within the canister i aremovable cartridge 60 which contains the purifying chemicals and fromthe outlet of the chamber a check valve Bl permits the return of the airthrough pipe 350 to mouthpiece 57. Even though the check valves arelocated in remote ends of the pipes 338 and 350 respectively, theynevertheless maintain a unidirectional flow of gases through said pipesto and from the mouthpiece.

In this device there is no means for supplying air under pressure sincethe device is intended only for light work either out of water or inshallow water. The oxygen is housed in the cylinder 40 as abovedescribed, which is supplied with a shut-off valve 4|, and reductionvalve 42 beyond which a pipe 63 leads to pipe 64 which affordscommunication between the bellows 58 and the end of the canister 380.

In the diving bell 65 (Fig. 6) the breathing of the operator isunconfined and the air is purified by circulating the air within thebell constantly through the mass of chemicals at 63 by means of a fan61. Similar apparatus may be used in 'caissons and other confinedplaces.

possible to provide a gauge.

The oxygen cylinder 40 with its usual cut-off valve 4| and reducingvalve 42,supplies oxygen to a metering orifice at 45 from which theoxygen oxygen, as may be the case when there is'any' unusual exertionrequired of the occupants, the occupants may open the by-pass valve 49to permit an additional flow of oxygen from the'cylinder 40 directlyinto the interior of the bell without changing the setting of themetering valve 45 or reducing valve 42 which normally maintains aninflow of oxygen exactly calculated to serve the requirements of theoperator or operators.

It is not easy for the operators to ascertain by their own feelings whenthe supply of oxygen is becoming deficient or excessive. As a means ofindicating th proportion of oxygen in the air which they are breathingwithin the bell, it is Two such gauges are shown in Figs. 6 and 7respectively, which may be used either in the diving suit or in thebell.

In Fig. 6, I have illustrated three small cages .at 10, 1| and 12,within which I have provided three small balloons inflated to likedimensions under like pressures. These balloons contain varyingproportions of oxygen and inert gas. For example, the balloon in cage 10may contain thirty percent of oxygen and seventy percent of helium. Theballoon in cage ll ma contain twenty-one percent of oxygen andseventynine percent helium. The balloon in cage 12 may contain fifteenpercent oxygen and eighty-five percent helium. As the heavy oxygenconstituent of the air within the diving bell or other enclosure varies,its buoyancy will vary and accordingly the balloons will rise or fall toindicate the approximate proportions of the constituents of the air. Theballoons are indicated in the positions which they will occupy for onedesirable range of oxygen content. If the balloon in cage Ill shouldrise it will indicate the presence of an excess of oxygen. If theballoon in cage 1I should fall it would indicate an oxygen deficiencywhich would become extreme if the balloon in cage 12 should fall.

The gauge shown in Fig. 7 uses a single balloon at 13 inflated with amixture of gases and including oxygen and helium or other inert gasbuoyed from a carefully balanced pointer jl which is pivoted andsuspended by a very light spring at I5. The free end of the pointermoves over a calibrated scale 16 which wou d indicate the proportion ofoxygen in the air on which the balloon 13 is buoyed.

As above indicated, helium is preferred to nitrogen as an inert gas withwhich to make up the artificial air to be used within th respiratoryapparatus and stored under high pressure in the flask 52 or 68. It isimportant that such air con tains oxygen in the desired proportion tothe inert gas also contained therein so thatwhen auxiliary air isintroduced to compensate for a change in pressure it is not necessary tovary in any way the normally automatic feed of oxygen into theapparatus.

It is also important that the oxygen contained in the air pressure tankis not relied upon to supply the metabolic requirements er the user. Ifit were, it would be necessary either to make up a mixture excessivelyrich in oxygen, which would involve a mixing problem, or to expel fromthe diving suit the proportion of inert gases which would becomeexcessive as the oxygen was consumed. This would necessitate too bulkyand heavy storage flasks.

Respiratory apparatus embodying this invention is self-contained in thesense that it may be worn or used without requiring supply lines. Theoperator is unhampered and unrestricted in the sense that he would be ifhe were requiredto maintain a hose affording communication between hishelmet and a source of air supply.

The indicating apparatus herein disclosed will function satisfactorilywhen helium is used as the inert gas for admixture of oxygen toconstitute the artificial air breathed by the operator. The molecularweight of oxygen is 32 and the weight of helium is only 4. Consequentlya comparatively slight change in composition of the air will result in avery substantial change in its buoyancy. The change in buoyancy would bemuch less easily perceptible if the oxygen were mixed with nitrogen.

In the apparatus shown in Figs. 4 and 5 the apparatus should preferablybe flushed with pure oxygen before being used. The necessity ofadmitting additional oxygen in this apparatus would be indicated by thepartial collapse of the bellows. In this device, which can be used downto a depth of sixty feet for a period. of three hours without injury,the admission of oxygen is preferably under the direct control of theoperator, no automatic control being provided. Optionally,

. this apparatus can be used for some purposes in connection with thecomplete diving suit. This would make it unnecessary to employ a bellowsand the compression tank 52 could be eliminated or, like tank 40, itcould be filled with oxygen.

Similarly in Fig. 3, in which the air pressure is used only to distendthe bellows 58, it is possible for some purposes, to dispense with theair and to use pure oxygen as in Fig. 5.

While I have referred to the flask or compression chamber 40 ascontaining pure oxygen, it will be understood that a mixture of gasesextremely rich in oxygen might be substituted without change inprinciple so far as the broad purposes of the invention are concerned,this being in contradistinction to the use of flask or compressionchamber 52 for the storage of air or other gaseous mixtures of an oxygencontent substantially like that required by the operator, so that thecontrolled admission of the air from this tank will not disturb thebalanced rate of oxygen admission from the other tank.

I claim:

1. A respiratory system comprising means pro viding a closed respiratorycircuit, an oxygen pressure chamber communicating with said circuit andprovided with means for automatically supplying substantially constantlyin accordance with the operators requirements a predetermined admissionof oxygen to said circuit, and an air pressure chamber communicatingwith said circuit and provided with a control valve independent of saidoxygen supplying means and independently manually operable for theadmission of air to said circuit for controlling the pressure therein,said air pressure chamber containing air having an oxygen contentsubstantially corresponding to the operators requirements, whereby theadmission of air to the circuit will not upthereto, said systemcomprising a self-contained portableunit, all of which is assembled tobe -mean comprising a flexible wall in said system,

together with means for supplying oxygen to said system at asubstantially constant rate proportioned to th consumption of oxygen insaid system by respiration and independent means for varying thepressure exerted interiorly of said system on said wall, saidindependent means comprising a source of air under pressure in excess ofthat to which said system is subject, said air containing oxygen insubstantially the proportion at which oxygen is maintained in saidsystem by said oxygen supplying means, the whole device being unitarilyassembled for selfcarrying by the user, and said independent pressurevarying means including a valve controlling the admission of air to saidsystem and directly manually operable by the person carrying the system.

3. A diving helmet provided internally with a mask for controlling theusers inspiration and expiration, an air conditioner communicating withsaid mask, and valve means controlling such communication for inducingunidirectional air flow between said conditioner and mask.

4. In a device of the character described, the combination with a divinghelmet, of an internal mask adapted to fit the divers face to receivehis breath and return to him air for breathing, air

conditioning apparatus, and means built into said helmet providingcommunication from said mask to said apparatus and from said apparatusto said mask, said means including air passage means provided with checkvalve means for unidirectional flow, said passage means communicatingwith the interior of said helmet and said helmet having an extensionprovided with a flexibl wall.

5. The combination with an enclosure containing air in predeterminedvolume comprising oxygen in predetermined proportion, of carbon dioxideabsorbing means, means for admitting oxygen substantially constantly tosaid enclosure at substantially the rate of oxygen consumption, wherebyto avoid substantial change of volume, and means for admitting aircontaining oxygen in substantially said proportion whereby to vary thevolume of air without substantial change of oxygen proportion, saidenclosure and mean being mechanically connected in unitary assembly andsaid air admitting means comprising a valve operable independently ofsaid oxygen admitting means and positioned to be directly subject to thecontrol of a person providing the air of said enclosure.

6. A device of the character described, comprising a closed respiratorycircuit including a respiratory chamber having chemical means forabsorbing carbon dioxide from the air in said circuit, means fordirecting air circulation in said circuit over said chemical means, anoxygen tank containing oxygen under pressure, and means afiordingcommunication between the tank and circuit and comprising a reducingvalve and a metering orifice for introducing oxygen into the air of saidcircuit at a substantially constant rate substantially proportioned tothe rate of consumption of oxygen from said air in respiration, wherebythe introduction of oxygen does not vary the volume of air in saidcircuit, together with a by-pass pipe and a control valve for theemergency admission of additional oxygen from said tank to said circuitwithout disturbing the setting of said reducing valve and orifice.

7. In a device of the character described, the combination with a divinghelmet, of an internal mask adapted to fit the operators face, toreceive his breath, and to return to him air for breathing, airconditioning apparatus, and means built into said helmet providingcommunication from said mask to said apparatus and from said apparatusto said mask, said air conditioning apparatus including means forabsorbing carbon dioxide and means for supplying oxygen to the air at asubstantially constant rate substantially proportioned to theconsumption of oxygen by the operator, means for augmenting the supplyof air without substantial change of oxygen proportion, and means builtinto the helmet providing closed circuit communication from said mask tosaid apparatus and from said apparatus to said mask, said meansincluding air passage means provided with check valve mechanism forunidirectional flow, said passage means communicating with the interiorof the helmet and the helmet having an extension provided with aflexible wall.

8. A completely self-contained respiratory system comprising thecombination with a breathing chamber applicable to the person of a user,of means providing a closed respiratory circuit including said chamberand substantially open'to operate at substantially equal pressuresthroughout, said circuit including means for removing carbon dioxidefrom air circulating therein-and means providing a flexible wall wherebypressures in said circuit approximately correspond to externalpressures, an oxygen pressure chamber communicating with said circuit,means controlling fiow from said oxygen chamber to said circuit at arate adapted to maintain substantially continuous oxygen deliveries tosaid circuit at a rate approximately equal to metabolic requirements ofthe user, and means independent of said oxygen flow-controlling meansfor regulating pressures within said chamber, said pressure regulatingmeans comprising an air pressure chamber communicating with said circuitand an independent control valve for the admission of air to saidcircuit, said air pressure chamber containing air having an oxygencontent substantially corresponding to metabolic requirements of saiduser, whereby the admission of air to the circuit will not upset thepredetermined rate of supplying oxygen thereto.

9. A self-contained respiratory system comprising, in unitarily portableassembly adapted to be carried by the user of th system, the combinationwith a respiratory air circuit having a breathing connection availableto the user and open to function at approximately equal pressuresthroughout and having a flexible wall. whereby the pressures within saidcircuit will approximately correspond to external pressure; of means formaintaining the oxygen content of air in said circuit substantiallyconstant and comprising carbon dioxide eliminating means, a reservoir ofoxygen under pressure, and means for the introduction of oxygen to thecircuit substantially continuously at a rate satisfying metabolicrequirements of said user; and means for increasing air pressures withinsaid circuit in accordance with increase in pressures externally of saidchamber whereby to keep said wall from undue distortion, said pressureincreasing means comprising an air pressure reservoir containing airunder pressure and having an oxygen content substantially correspondingto said metabolic requirements, and means including a separate andindependently operable valve providing con trolled communication betweensaid air pressure reservoir and said circuit wholly independently of theadmission of oxygen to said circuit from said oxygen reservoir, saidvalve being operable solely to increase pressures within said circuitwithout affecting the proportionate oxygen content of air in saidcircuit.

10. A respiratory system comprising in unitarily portable combination aseries of elements assembled for carrying by the user of the system;said combination of elements comprising elements constituting a closedrespiratory air circuit including a breath receiving and deliveringmeans personally applicable to a user, a flexible wall, and purifyingmeans for removing carbon dioxide from air in said circuit; an oxygenreservoir element communicating with said circuit and containing oxygenunder pressure and provided with means for automatically releasingoxygen substantially constantly to said circuit at substantially therate of metabolic requirements; and pressure determining elementsentirely independent of said oxygen reservoir element and the controlthereof, said pressure determining elements comprising a reservoircontaining under pressure higher than the maximum to which said flexibleWall is subject a supply of air containing oxygen substantially in theproportion required to satisfy metabolism of said user, and a valvepositioned to be freely accessible for manipulation by a person carryingthe system, said valve being independent of the oxygen supplying elementand bein adapted to be opened and closed as required to raise thepressure in said circuit to a pressure sufficient to compensate forexternal pressures on said flexible wall without varying thepredetermined ratio of oxygen in said circuit.

11. A respiratory system comprising a self contained unitary combinationof elements assembled for carrying by the person using the systems, saidcombination of elements including elements constituting a closedrespiratory air circuit containing a flexible wall; a pressureregulating element for maintaining pressures within said circuit atvalues compensatory for increasing external pressures to which said wallis subject and comprising an air reservoir containing under pressureexceeding such external pressures air having an oxygen content inpredetermined proportion to meet metabolic requirements, and valve meansaccessible to a person carrying said system for the controlled admissionof such air iii) to said circuit; oxygen maintaining elements operableindependently of air admission to said circuit for maintaining asubstantially constant proportion of oxygen in the air of said circuitapproximately corresponding to the proportion of oxygen in the air ofsaid reservoir, said last-mentioned element including carbon dioxideeliminating means exposed to the air traversing said eircut, an oxygenreservoir containing oxygen under pressure, and means for the controlledadmission of oxygen substantially constantly to said circuit at a rateto satisfy metabolic requirements by replacing oxygen converted byrespiration into carbon dioxide and removed as carbon dioxide from saidcircuit.

12. The device of claim 11, in which the oxygen maintaining elementscomprise a by-pass pipe from the oxygen reservoir to the air circuit,and a control valve for said by-pass pipe directly subject tomanipulation of the person using the system for the emergency admissionof additional oxygen to the circuit without disturbing the rate ofcontrolled oxygen admission a provided in the structure of claim 11.

13. A respiratory system comprising a self -containing unitarycombination of elements assembled for carrying by the person using thesystem, said combination of elements including elements constituting aclosed respiratory air circuit containing helium and oxygen in aproportion to satisfy the metabolic requirements of the person using thesystem, said circuit including means making the air of said circuitaccessible to said person, an air reservoir containing under pressurehelium and oxygen in substantially the proportion in which such heliumand oxygen are incorporated in the air of said circuit, means includingan air valve directly accessible to a person carrying the system for thecontrolled admission of air from said reservoir to said circuit, acarbon dioxide eliminating means exposed to the air of said circuit, anoxygen reservoir, and means for the controlled and substantiallyconstant admission of oxygen from said reservoir at a rate to maintainsaid predetermined proportion of oxygen and helium in the air of saidcircuit, said oxygen admitting means and said air valve being entirelyindependent, whereby the helium and oxygen content of the air of saidcircuit will be maintained automatically substantially constant duringth use of said circuit by a person carrying the system, irrespective ofpressure, the oxygen consumed being replaced and the helium conserved,and whereby the pressure in said system may be increased subject to thedirect control of the user without disturbing the proportion of oxygenand helium in said circuit.

MAX EUGENE NOI-IL.

